title: Top-hat beam output of a single-mode microstructured optical fiber: impact of core index depression.
abstract: A new strategy to obtain a single-mode fiber with a flattened intensity profile distribution is presented. It is based on the use of an OVD-made high index ring deposited on a silica rod having a refractive index slightly lower than the silica used for the microstructured cladding. Using this strategy, we realized the first single-mode fiber with a quasi-perfect top-hat intensity profile around 1 µm. Numerical studies clearly demonstrate the advantage of using a core index depression to insure the single-mode operation of the fiber at the working wavelength.
authors.forename: Constance
authors.initials: C
authors.lastname: Valentin
authors.forename: Pierre
authors.initials: P
authors.lastname: Calvet
authors.forename: Yves
authors.initials: Y
authors.lastname: Quiquempois
authors.forename: Géraud
authors.initials: G
authors.lastname: Bouwmans
authors.forename: Laurent
authors.initials: L
authors.lastname: Bigot
authors.forename: Quentin
authors.initials: Q
authors.lastname: Coulombier
authors.forename: Marc
authors.initials: M
authors.lastname: Douay
authors.forename: Karen
authors.initials: K
authors.lastname: Delplace
authors.forename: Arnaud
authors.initials: A
authors.lastname: Mussot
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Hugonnot